MP7 feeding but not all the way? Also, hop up issue?

I know that another guy recently posted a similar problem with his mp7. Mine is similar but a little bit different. My MP7 worked great for months (bought it used from a friend but all of a sudden after I went to a cqb game a few months ago this problem has occurred.

I put in a full mag of gas and bbs, charge the handle back, and fire off a shot. The first shot is always straight and perfect, but after that, after approximately 60 feet the bbs shoot straight up into the air. I have tried many different hop up positions and it keeps happening no matter what.

But what usually happens is right after I adjust the hop up and shoot another few shots, the gun just stops feeding. This is after around 12 shots from the first mag. The mag feeds fine and the nozzle pushes it into the barrel, but it doesn't get past the start of the barrel. The bbs keep feeding, but push the other bbs further into the barrel. They do not roll out of the barrel at all. so i have to push them back into the gun with the unjamming rod. When I do this, all the bbs I shot come back out. I have cleaned the barrel countless times but nothing.

I feel like it may be the common swollen bucking issue but I'm not sure. I have heard the mp7 barrel assembly is a bitch to take out, but I'll look up some videos and check out the bucking. But any other insight you guys can give me would be helpful. Thanks!

Yea I use propane. And I have used silicone in the past sprayed on the cloth I put in the cleaning rod. But I mostly use warm soapy water and then dry cloth (Pieces of T-shirt). I'll check out the bucking tomorrow and post again.

Yea I use propane. And I have used silicone in the past sprayed on the cloth I put in the cleaning rod. But I mostly use warm soapy water and then dry cloth (Pieces of T-shirt). I'll check out the bucking tomorrow and post again.

Based on you answer and the description og the issue you have a swollen bucking.

I would bet on it being a swollen bucking. Actually taking the MP7 apart isn't so bad. People make it sound harder than it really is. There's a good video about it on here. The only tricky part is getting the trigger back in, which is easy once you learn the trick. You just need to get it positioned right and push it all the way in, and push it back. It's really hard to explain, just play with it. Putting it in with the gun on semi or full instead of safe is easier too.